Starting device for internal-combustion engines



C. G. T. THELIN.

STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DE02, I9I8.

Carl GUSJILTOI-Iwre -TxfrItn BI @ffii/UI IW UNITED, STATES `PA'rsivr OFFICE. j

CARL GUSTAF THURE THELIN, OF STOCKHOLM, VSWEDEN, ASSIGNOR TO ARTHUR EDWIN KRISTOFER SPNGBERG, OF STOCKHOLM, SWEDEN.

STARTING DEVICE FOR INTERNAL-COMBUSTION ENGINES.

To all whom t may concern:

Be it known that I, CARL GusrAr THURE THELIN, a subject of the King of Sweden, residing at Stockholm, in the Kingdom of Sweden, have invented a new and useful Improvement in Starting Devices for Internal- Combustion Engines, of which the following is a specification.

The present invention relates to a starting device for four-cycle internal combustion engines, such as for instance Diesel engines, of the type which are started by means of compressed air or another pressure agent, and which are provided in ordinary manner with a regulating shaft driven by the crank shaft of the engine and on which cams or cam disks are secured which serve for operating the various valves of the engine, such as starting, suction, fuel and exhaust valves. For the purpose of starting engines of the said kind the compressed air, or the pressure agent otherwise used, must be in troduced into at least one of the cylinders of the engine during the period of expansion in said cylinder, which period thus also constitutes the starting period. In ordinary engines of this type provided with l to 5 cylinders, however, the said starting periods can not follow so closely on one another that there will always, that is to say, at all positions of the crank shaft, be one cylinder ready for starting in one direction of movement or in both directions. Hence, when the engine has stopped with its crank shaft in a position unfavorable for starting, it is often necessary to turn the crank shaft by hand so that one of the cylinders becomes ready for starting. K

To render such turning of the crank shaft unnecessary, it has already been proposed for initiating the starting to turn the regulating shaft ofthe engine relatively to the crank shaft. In this manner it is thus possible to change the period of the cylinder in which compressed air is first to be introduced for the purpose of starting. to period of expansion, in case the said cylinder is in the period of suction corresponding to the desired direction of movement.

In the accompanying drawing Figure l is a diagram of the cranks of a three-cylinder engine, and Figs. 2 and 3 illustrate by way of example a suitable embodiment of the present invention, Fig. 2' showing the g Specification of Letters Patent. Patented Jul, 29, 1920. Application led December 2, 1918.

Serial No. 264,979.

clutch. of the starting device disengaged, and Fig. 3 showing the clutch throwngin.

If, in the instance of a three-cylinder engine the crank shaft of which has stopped in the position illustrated in Fig. l of the attached drawing, starting is to be effected in the direction of the arrow shown adjacent the crank l, but the cylinder corresponding to the said crank is in the period of suction, its suction valve thus being open, the regulating shaft is first turned' half a rotation. By this turning the period of the cylinder corresponding to the crank l is changed from suction to expansion during which latter period the starting valve may open during a certain angle when the crank has passed the upper dead point, for the purpose of admitting into the cylinder the compressed air used for the starting. The said turning of the regulating shaft having been. effected, the starting valve is rapidly put into operation by means of a special device which is also used for disconnecting the said valve when the ignition has taken Aplace in the engine. Again, if the engine is to be started, for instance, in the direction of the arrow shown adjacent the crank 2, and if the corresponding cylinder is not in the period of expansionthe same course of operation as above described is followed.

The purpose of the present invention is to provide a starting device by means of which the said turning movement of the regulating shaft may be effected in a convenient and safe manner. The invention consists broadly in this that the regulating shaft supporting the cam-disks is connected with a special device for turning the same relatively to the crank shaft after disengagement of a clutch connecting said two shafts, said device cooperating with the clutch in such manner that on disengagement of the clutch said device `becomes connected with the regulating shaft, but becomesdisconnected from said shaft when the clutch is thrown in.

The crank shaft 4 is connected by means of a toothed gearing 5. 6, 7 with the regulating shaft. This shaft is divided into two portions 8 and 9 the former 8 of which is driven by the crank shaft 4 by means of the said gearing. `On the second portion 9 vwhich is placed in alinement with the portion 8, the cam disks l0 are secured which operate the valves of the engine. The portion 8 of the shaft is provided with a clutch disk 11, and the portion 9 carries a corresponding clutch disk 12, the said two disks being located opposite one another and provided with holes 13 for two or more clutch studs 14;' secured to a sleeve 15 movable longitudinally on the portion 9, so that by moving the sleeve 15 the studs 1st may be moved through the holes in the disk 12 into or out of the holes in the disk 11, when the holes in the said disks are opposite one another which takes place, in the embodiment shown, at every half turn of a rotation of one of the shaft portions relatively to the other. A helical spring 16 is placed around the portion 9 the said spring tending to push the sleeve 15 to the left in Figs. 2 and 3 and thus to move the clutch studs 1li into engagement with the holes in the disk 11. The moving of the sleeve in the opposite direction for disengaging the clutch is effected by hand by means of a lever 17. A beveled gear wheel 18 is secured to the sleeve the said gear wheel being moved, when disengaging the clutch, into engagement with a secondv beveled gear wheel 19 secured to the shaft of a hand-wheel- 20 journaled in a stationary support, the said hand-wheel serving for turning the portion 9 of the shaft when the clutch has been disengaged'.

Then it is desired to turn the portion 9 of the regulatingshaft 'together with its cam disks relatively to the portion S'of the shaft geared to the crank shaft 4t, it is thus only necessary by means of the lever 17 to disengage the clutch 1,1-14, the portion v9 hecoming geared to the hand-wheel Q() whereA by it is now possible to turn the portion 9 half rotation for producing the desired change of period. 1When the lever is released the clutch is automatically thrown in and the hand-wheel Q0 is simultaneously disconnected from the portion 9 of the shaft. v

rihe embodiment illustrated may of con rse be modiiied in several respects without departing from the principle of the invention. lf foriinstance the clutch between the two portions of the shaft is provided with more than two studs, these studs are to be placed at such distances from one another that the clutch members may be thrown into engagement only at every half rotation of the shaft portion 9. Finally, it is not necessary, of course, to divide the regulating shaft into two portions, but the gear wheel i may instead be loosely mounted on the shaft, and it may be combined with a device for` connecting it to the shaft in diderent positions, or the gearing 5 7 maybe arrangedl in other manner so that the crank sha-,ft and the regulating shaft may be disengaged from the connection with one another for the. pnrpose of turning the regulating shaft.

I claim:

1. In a starting device for four-cycle internal combustion engines of the type started by means of com-pressed air or the like, the combination with a crank shaft, of a regulating shaft, a gearingv interposed between said crank shaft and said regulating shaft, camson said regulating shaft for operating the various valves of the engine, a clutch between said crank shaft and said regulating shaft said clutch enabling said shafts tobe connected to one another in different angular positions, and a device con nected with said regula-ting shaft for tu y ing the same relatively to said crank sh.V 9*' said device cooperating with clutch in such man-ner that it is coni cted to said regulating shaft when 'the clutch is d` gaifged but is disconnected from said shaft when the clnteh is thrown in. f

2. In a starting device for four-cycle internal combustion engines of the type started by means of com-pressed air ol 'the like, the combination with a crank shf. 't, of a regulating shaft, a gearing interposeiv tween said crank shaft and said regula` shaft, cams on said regulating shaft f erating the various valves of the e1` clutch between said crank shaft and regulating shaft said clutch enablii g' said shafts to: be connected to one another in differeinJ angular positions, and a device connected with said regulating shaft for turnfing the same relatively to sai-d crank shaft, said device comprisingl a gear wheel mov able on said' regulating shaft and connected with said clutch, a second gear wheel located so as to be engaged by said hist-mentioned gea-r wheel when moved for disei c f'enient of said clutch, and a hand wheel cV .nected with said second gear wheel.

3. In a starting device for tour-cycle internal combustion engines of the type started by means of eompressed air or the like, the combination with a crank shaft, of a regulating shaft divided into two portions, a gearing interposed between one of said portions and the. crank shaft, cams on the second portion of said regnlating shaft for operating the various valves` ot the engine, a, clutch between said two portions4 of said regulating shaft said clutch enabling the said portions to bey connected to one another in different angular positions, and a, device `connected with said second portion of said regulating shaft for turning the same relatively to the first portion, said device coperating with the elntch in such manner that it is connected to the said ser:- ond portion when the clutch is disengaged but is disconnected from said portion when the clutch is thrown in.

CARL GUSTAF THURE THELIN. 

